Roof support for underground mines and openings



y 1970 c. c WHITE 3,509,726

ROOF SUPPORT FOR UNDERGROUND MINES AND OPENINGS Filed June' 25, 1969 4 Sheets-Sheet 1 ju unfinEufinnsln nam III E i i E E L E :2 I 2 @1 m i F gl m E O 6! Ni A p3 5 I i 1R0 E III M 5 v h 1 E i N n ii IN 5 l W I nwsmozz 4 A A w 3 a l Claude CW/ute ATTORNEYS y 1970 c c. WHITE 3,509,726

ROOF SUPPORT FOR UNDERGROUND MINES AND OPENINGS Filed June 25, 1969 4 Sheets-Sheet 2 In E u lg rs 1 R n L s j u I: 1 i I Ill i 21 ,3. a; E I

@HEWEKHEUEWEIEMQ F3H-EHHQQWEHHEJHEW MENTOR a; 'Q/quge 6. White ATTORNEYS May 5, 1970 c. 0. WHITE 3,509,726

ROOF SUPPORT FOR UNDERGROUND MINES AND OPENINGS Filed June 25, 1969 4 Shets-Sheet 5 Fig. 3

INVENTOR. Claude C. Whl'f Attorneys May 5, 1970 c. c. WHITE ROOF SUPPORT FOR UNDERGROUND MiNEs ANDOPENINGS Filed June 25, 1969 4 Sheets-Sheet 4 Claude C Wh/fe ATTORNEYS United States Patent Cl. 61--45 16 Claims ABSTRACT OF THE DISCLOSURE A roof support for underground mines and openings embodying anchor members embedded in holes drilled in spaced, opposed relationship in the roof of a mine passage or opening. A roof bolt is inserted in each hole, the upper terminal of each bolt being engaged with an anchor member. The bolts extend downwardly through the holes to a point adjacent the mine roof, at which point they extend through a collar member. A horizontal reinforcing member extends between the holes, and the terminals are provided with straps adapted for fixed engagement with each collar. Upon tightening of the anchor members, substantially equal tension is applied to the anchor members and horizontal reinforcing member to create a re sultant upward and inward force on the mine roof.

This invention relates to a roof support for underground mines and openings, and is a continuation-in-part of application Ser. No. 796,775 filed Feb. 5, 1969'.

Objects It is an object of this invention to provide a roof support for underground mines and openings comprising a truss utilizing the inherent compressive strength of the roof masonry, the truss being so arranged to produce an upward and inward force on the roof above the mine opening, thereby preventing collapse of the roof.

Another object is to provide a roof support including anchor members installed in holes in a mine roof in opposed relationship to each other, rod members engaged with the anchor members extending downwardly through the holes, a collar sleeve engagement with the lower portion of at least one of the rod members, a strap mem ber engaged with the collar, and a horizontal member connecting the strap to the opposite rod member.

A further object is to provide a roof support as described wherein both rod members are roof bolts, and collars and strap members are engaged with each roof bolt.

A further object is to provide a roof support of the character described, wherein the collar and strap members may be readily assembled and installed rapidly with a roof bolting machine of conventional structure, the installation being readily effected above a continuous mining machine from the mine opening.

A still further object is to provide means for securely holding the strap terminals forming the horizontal reinforcing member of the assembly in fixed relationship to each other, so that, upon tightening of the roof bolts, the straps will be drawn up into the holes, thus tensioning the horizontal reinforcing member with approximately the same tension as exerted on the 'bolts, thereby creating a resultant upward and inward force on the mine roof.

Other objects will be manifest from the following description of the presently preferred forms of the invention taken in conjunction with the accompanying drawings.

3,509,726 Patented May 5, 1970 Description of figures of drawings FIG. 1 is an elevational view of the roof support of the present invention illustrating this application;

FIG. 2 is a view similar to FIG. 1 of a modified form of the present invention;

FIG. 3 is an enlarged elevational view of the present roof support, illustrating to advantage the collar and strap forming a part of the present invention;

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 3, looking in the direction of the arrows;

FIG. 5 is a perspective view of a portion of the roof support of the present invention, portions thereof being broken away and this assembled for purposes of clarity;

FIG. 6 is a side elevational view of a strap forming a part of the present invention;

FIG. 7 is an end elevational view of the strap of FIG. 6;

FIG. 8 is an end elevational view of the strap of FIG. 6, taken from the opposite end from that illustrated in FIG. 7;

FIG. 9 is a sectional view taken along the line 99 of FIG. 6, looking in the direction of the arrows;

FIG. 10 is a top plan view of a collar forming a part of the present invention;

FIG. 11 is a longitudinal sectional view taken along the line 1111 of FIG. 10, looking in the direction of the arrows;

FIG. 12 is an end elevational view of the same;

FIG. 13 is a sectional view taken along the line 1313 of FIG. 11, looking in the direction of the arrows; and

FIG. 14 is a sectional view taken along the line 14-14 of FIG. 11, looking in the direction of the arrows.

Description of invention In FIG. 1 there is illustrated one form of the present invention, showing the application of the present roof support to a mine passage or opening 20, having pillars 22 and a roof 24, in which is installed a plurality of spaced roof supports generally designated 26 which extend laterally of passage 20 at spaced intervals.

In accordance with the objects of this invention, holes 2 8 and 30 are drilled in mine roof 24 in opposed relationship to each other, the holes drilled upwardly and outwardly at approximately a 45 angle from the lower extremity of the roof. As shown to advantage in FIG. 1, the lower part of the opening at roof level, is spaced from pillars 22, and the upper limits of the holes extend to a point in the roof above pillars 22.

The roof support of the present invention includes roof bolts 32 of conventional construction having a washer 34 and head 36 fixed to one end thereof, the opposite end of the bolt being threadedly engaged with an anchor member 38 which is preferably of the expanding shell type.

In accordance with the present invention, and as illus trated in FIGS. 3 and 5, a collar generally designated 40 is sleeved over the lower portion of the shank of each roof bolt 32, adjacent washer 34.

As shown to advantage in FIGS. 10* to 14, collar 40 includes a generally cylindrical body 42 having a longitudinal bore 44 extending therethrough, the bore being adapted for the passage of the shank of bolt 32. Adjacent, but spaced from, one terminal portion of the cylindrical body there is provided an elongated slot 46 in the upper face of the cylindrical body, aft of which the body is enlarged at 48, to provide a bore section 50 in communication with bore 44. The cylindrical collar terminates in a boss portion 51 which is of reduced size.

For cooperation with collar 40, there is provided a strap 52 which includes a main body portion 54 which, as shown to advantage in FIG. 9, is of arcuate conformation in cross section. One terminal of main body portion 54 is enlarged to provide an abutment member 56. The opposite terminal of main body portion 54 is progressively enlarged as indicated at 58. Progressively enlarged section 58 issues into a cylindrical terminal portion 60, the extreme limit of which is enlarged at its upper extremity to provide a stop 62.

Associated with strap 52, there are provided header plates 64, (see FIG. 3) made of wood or other suitable material, each header plate being mounted on a horizontal support 66, one terminal of which is turned upwardly to provide a flange 68. Portions of support 66 are struck downwardly to provide clip members 70 engageable with opposed peripheral portions of strap 52 to retain the header plates in position.

It will be noted that straps 52 are bent inwardly towards each other at a point below the roof line of the mine opening for engagement with a connecting horizontal support member 72. Connection of the horizontal support member to the straps is effected by means of wedge assemblies 74.

Each wedge assembly is preferably of similar construction to that disclosed in my copending application Ser. No. 796,775, and, as illustrated in FIG. 5, includes a wedge box 76 having spaced planar side walls and arcuate upper and lower walls, providing an oval shaped opening within the box. The upper wall lies in a lateral plane which extends at an angle to the plane of the lower wall so that the cross-sectional area of the opening within the box progressively increases from one end to the other.

A wedge 78 with a lower arcuate surface complemental to the arcuate lower wall of wedge box 76, is adapted for insertion into the opening of the wedge box, the upper surface of the wedge being flattened and serrated at 8 to complement and intermesh with a corresponding flattened and serrated surface 82 of horizontal connecting member 72. By this arrangement, upon a tightening force being exerted on strap 52, a force is exerted by stop 62 against wedge box 76 in a direction to hold horizontal connecting member 72 and strap 52 in fixed relationship to each other.

Operation In the installation of the roof support of the present invention, strap 52 is inserted through the large core sectiOn of each collar 40, in the manner illustrated in FIG. 5, following which roof bolt 32 is passed through elongated slot 46 of collar 40. The arcuate surface of strap 52 complements, and lies in contiguous engagement with, the outer periphery of roof bolt 32, (see FIG. 4}, thereby permitting only relative longitudinal movement of strap 52 with respect to collar 40. This longitudinal movement is limited by the engagement of abutment 56 of strap 52 with the adjacent terminal portion of collar 40.

Anchor member 38 may then be threadedly engaged with the inner terminal of bolt 32, following which it may be inserted in hole 28 of the mine roof. At a point below the roof line, strap 52 is bent upwardly and inwardly to lie in opposed relationship with a like member, as shown to advantage in FIG. 1. Header plates 64 and supports 68 may then be positioned between the straps and the mine roof. Connecting member 72 is then joined at each of its terminals with opposed straps by means of wedge assemblies 7 4.

Each bolt is then tightened to effect anchoring engagement of members 38 with that portion of the mine roof surrounding opening 28. Tightening of each bolt also efiects drawing the straps up in to the hole slightly, thereby tensioning the connecting strap with approximately the same tension as is applied to the bolts.

In this way, a resultant upward and inward force is exerted on the roof in the direction indicated by the arrows designated A of FIG. 1. Header plates 64 exert a vertical force on the roof indicated at B of FIG. 1. There is thereby produced a truss-like elfect on the mine roof for holding the latter up without the use of Wooden or steel beams, or other extraneous devices used in the past.

In FIG. 2, there is illustrated a slightly modified form of the roof support of FIG. 1, and accordingly, like parts are identified by like, primed members.

In this form of the invention, however, only one roof bolt 32' is employed in a roof support unit, one anchor member 38 being threadedly engaged With a tubular rod 84, for expanding the former. The lower portion of rod 84 is bent inwardly at a point below roof 24' as indicated at 86, and extends to a point adjacent horizontal connecting member 72'. Rod portion 86 and connecting member 72' are joined by a connector 88.

Installation of this form of roof support is effected in substantially the same manner as the form of invention illustrated in FIG. 1, and the upward and inward, and upward forces exerted thereby are also alike, as shown by the force arrows designated A and B.

With the roof support of the present invention simple and economical means are provided for supporting a mine roof, which roof support may be readily and quickly installed and tightened by a conventional bolting machine above a continuous mining machine, thereby obviating the removal of the mining machine from the passage in which the roof supports are being installed. With this invention also, the tightening of the roof bolt and the horizontal connecting portion extending between the roof bolts is effected simultaneously, thereby automatically producing the application of approximately the same tension to both the roof bolts and the horizontal connecting members.

What I claim is:

1. A roof support for underground mines and openings having a roof and side pillars forming a passage, the support comprising:

(a) anchor members installed in holes in the mine roof above the passage in spaced, opposed relationp,

(b) opposed rod members engaged with said anchor members and extending downwardly through the mine roof holes,

.(c) a collar in sleeved engagement with the lower portion of at least one of said rod members, and connecting means extending between said collar and the opposite rod member.

2. The roof support of claim 1, wherein:

(a) both of said rod members are roof bolts, and

(b) collars are engaged with the lower portion of both of said roof bolts.

3. The roof support of claim 1, wherein:

(a) one of said rod members comprises a roof bolt, and

('b) the other rod member is a rod extending downwardly through one of the holes in the mine roof,

v(c) the rod being bent at a point adjacent the mine roof, and

(d) means for joining the rod terminal to said connecting means.

4. The roof support of claim 1, wherein said connecting means includes:

(a) a strap engaged with said collar,

(b) a connecting member engaged with a terminal of said strap, and

(c) means for joining the terminals of the connecting member to each strap.

5. The' roof support of claim '4, wherein said collar includes:

(a) a cylindrical body portion having a longitudinal bore through which said roof bolt passes,

.(b) the upper walls of said cylindrical body portion being provided with an elongated slot,

(c) a portion of the cylindrical body portion and bore being enlarged,

(d) said strap including a body portion for insertion through the elongated slot and enlarged bore of said collar,

(e) a terminal of said strap being enlarged to provide an abutment, whereby said strap is held in fixed relationship to said collar upon engagement of said abutment with a terminal of said collar.

6. The roof support of claim 4, wherein said means for joining the terminals of the connecting member to each strap includes:

(a) a wedge member joining at least one terminal of said connection member to a strap.

7. The roof support of claim 6, wherein:

(a) both terminals of said connecting member are joined to each strap by a wedge member.

8. The roof support of claim 6, wherein said means includes:

.(a) a connector threadedly engaged with adjacent terminals of said strap and connecting member.

9. The roof support of claim 5, with the addition of:

(a) a header plate interposed between each strap and the mine roof for exerting an upward force on the latter.

10. A roof support for underground mines and openings having a roof and side pillars forming a passage, the support comprising:

(a) anchor members installed in holes in the mine roof above the passage in spaced, opposed relationship,

(b) opposed rod members engaged with said anchor members and extending downwardly through the mine roof holes,

.(c) the lower terminals of said rod members being spaced from the pillars and the upper terminals thereof being located above the pillars,

(d) a collar in sleeved engagement with the lower portion of at least one of said rod members,

(e) a strap,

(f) one terminal of said strap being connected to said collar, and

(g) means for connecting the free terminal of said strap to the other of said rod members, and

(h) means for applying approximately equal tension to said means and rod members,

.(i) whereby a resultant upward and inward force is applied to the mine roof.

11. The mine roof support of claim 10, wherein:

(a) said rod members comprise roof bolts, and

( b) a collar and strap is applied to each of said roof bolts.

12. The roof support of claim 11, with the addition of:

(a) header plates interposed between said straps and the mine roof, for exerting an upward force on the latter.

13. A roof support for underground mines and openings having a roof and side pillars forming a passage, the support comprising:

(a) anchor members installed in holes in the mine roof above the passage in spaced, opposed relationship,

(b) said anchor members extending angularly to the mine roof with the uppermost portion thereof located above the pillars of the mine passage,

(c) opposed rod members engaged with said anchor members and extending downwardly through the mine roof holes,

((1) a collar in sleeved engagement with the lower portion of at least one of said rod members, said collar including,

(e) a cylindrical body portion having a longitudinal bore through which the roof bolt passes,

(f) the upper wall of said body portion being provided with an elongated slot,

(g) a portion of the body portion and longitudinal bore being enlarged from the elongated slot to one terminal thereof,

(h) a strap engaged with said collar, said strap includ- (i) a body portion of arcuate cross-section for insertion through the elongated slot and enlarged bore of said collar,

(j) a terminal of said strap being enlarged to provide an abutment, whereby said strap is held in fixed relation to said collar,

(k) connecting means joining the free terminal of said strap to said opposed rod member, and

(1) means for applying approximately equal tension to said rod members.

14. The roof support of claim 13, wherein:

(a) one of said rod members is a roof bolt.

15. The roof support of claim 13, wherein:

(a) both of said rod members are roof bolts, and

(b) a collar and strap are applied to each of said roof bolts.

16. The roof support of claim 13, with the addition of:

(a) header plates interposed between said connecting means and mine roof for exerting an upward force on the latter.

References Cited UNITED STATES PATENTS 2,667,037 1/ 1954 Thomas et a1. 61-45 2,771,746 11/1956 Fischer et a1 61--45 3,306,051 2/1967 Howlett 61-45 FOREIGN PATENTS 163,232 6/ 1955 Australia. 943,667 12/ 1963 Great Britain.

DENNIS L. TAYLOR, Primary Examiner US. Cl. X.R. 52-423, 229

Patent No. 3, 509, 726 Dated May 5, 970

Inventor(s) Claude C. te

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 1, line 10, cancel "a" and Substitute --an elongated--; line 12, after- "means" insert --secured to said collar and--.

Signed and sealed this llth day of January 1972.

(SEAL) Attest:

EDWARD M.FLETCHER, JR. ROBERT GOTTSCHALK Attesting Officer Acting Commissioner of Patents FORM PO-1050HO 69) USCOMM 0c aointhpog 

